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    <title>Document</title>
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  <body>
    <script>
      let scores = Number(prompt('请输入您的分数！'))
      if (scores >= 90) {
        alert(`您的成绩为：A`)
      } else if (scores >= 80 && scores < 90) {
        alert(`您的成绩为：B`)
      } else if (scores >= 70 && scores < 80) {
        alert(`您的成绩为：C`)
      }else if (scores >= 60 && scores < 70) {
        alert(`您的成绩为：D`)
      }else{
        alert(`您的成绩为：E`)
      }
    </script>
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